1. Field of the Invention
The present invention relates to an electronic component having a laminate in which an element substrate defining an electronic component element is bonded to a case plate using an adhesive. More specifically, the present invention relates to a method for manufacturing an electronic component in which an electrical connection structure between an electrode on the element substrate and an electrode on the case plate, and an electrical connection structure between the electronic component and an external device are improved, and also relates to the electronic component.
2. Description of the Related Art
Various semiconductor sensor devices in which a sensor having a three-dimensional structure is defined on a semiconductor substrate have been proposed. Such semiconductor sensor devices have a moving section, and need to be manufactured and mounted so as not to impede the movement of the moving section. Therefore, for example, a method in which the semiconductor substrate is accommodated in a ceramic package and the ceramic package is mounted on a mounting substrate and is bonded using a bonding wire has been used. However, due to the need for a ceramic package, this method inevitably causes an increase in size. Furthermore, the mounting on the mounting substrate using the bonding wire inevitably requires a large mounting space. In particular, a semiconductor sensor device having a large number of sections electrically connected to external devices requires a large mounting space based on a bonding wire on a mounting substrate.
Japanese Unexamined Patent Application Publication No. 2004-340730 discloses a semiconductor device 101 shown in FIG. 10. The semiconductor device 101 has a base substrate 102. A semiconductor substrate 103 including a semiconductor sensor is fixed on the base substrate 102. The semiconductor substrate 103 has a moving section including an electrode 103a. Although schematically shown in FIG. 10, a sensor section including the electrode 103a is a moving section. A recess is formed in a surface 103b of the semiconductor substrate 103 to define a gap A that faces the moving section of the semiconductor substrate 103. The semiconductor substrate 103 is fixed to the base substrate 102 so that the surface 103b having the recess defines a lower surface of the semiconductor substrate 103.
Electrodes 103c and 103d disposed on the semiconductor substrate 103 are bonded and electrically connected to electrodes 102a and 102b on the base substrate 102. The electrodes 102a and 102b are electrically connected to electrodes 102c and 102d disposed on a lower surface of the base substrate 102 via through-hole electrodes provided in the base substrate 102. Solder bumps 104 and 105 are bonded to the electrodes 102c and 102d. 
Side and upper surfaces of the semiconductor substrate 103 are sealed by a mold resin 106. The semiconductor substrate 103 is hermetically sealed by the base substrate 102 and the mold resin 106.
The semiconductor device 101 is mounted on a mounting substrate by mounting the solder bumps 104 and 105 on electrode lands on the mounting substrate. Therefore, the semiconductor device 101 can be mounted in a small mounting space on the mounting substrate.
In the semiconductor device 101 described in Japanese Unexamined Patent Application Publication No. 2004-340730, as described above, the semiconductor substrate 103 having a moving section is hermetically sealed by the base substrate 102 and the mold resin 105, and can be mounted on a substrate by a flip-chip bonding technique using the solder bumps 104 and 105. In this case, a relatively low bonding strength is obtained using the solder bumps 104 and 105. Therefore, it is necessary to fill an adhesive of epoxy resin or other suitable material, called an underfill, between the mounting substrate and the base substrate 102 to increase the adhesion strength.
As a result, the spacing between the mounting substrate and the base substrate 102 is filled with the underfill as well as the solder bumps 104 and 105. Stress applied to the mounting substrate is transmitted to the base substrate 102 through the solder bumps 104 and 105 and through the underfill, and consequently, to the semiconductor substrate 103. The influence of the stress, therefore, may cause the semiconductor sensor defined on the semiconductor substrate 103 to malfunction.